Path: utzoo!attcan!uunet!munnari.oz.au!cow!bmp From: bmp@cow.ecs.oz (Bruce Paterson) Newsgroups: sci.electronics Subject: Re: Hetro dining? Summary: Well actually.... Message-ID: <522@cow.ecs.oz> Date: 24 Sep 90 04:17:20 GMT References: <17660105@hpfcdj.HP.COM> Organization: Email Electronics, Melbourne, Australia. Lines: 24 Someone wrote: > >Sorry, but this is wrong. The 'super' in superheterodyne is actually > >a contraction of 'supersonic' referring to the fact that the > >heterodyne produced is above the range of audible frequencies (i.e. > >an RF heterodyne). In article <17660105@hpfcdj.HP.COM>, myers@hpfcdj.HP.COM (Bob Myers) writes: > An interesting theory, but I suspect that it's incorrect as far as the > actual origin of the word is concerned. When Armstrong invented the > superheterodyne technique, the most "refined" receiver type available > was called the "super-regenerative" (which, I assure you, had nothing to > do with regenerating supersonic frequencies - although the "regeneration" *did* > take place in the RF stages). I suspect that he simply picked up the "super" > prefix from this as a Good Marketing Move. Actually a super-regenerative receiver does have a bit to do with super-sonics. A straight regenerative receiver uses +ve feedback to increase the gain of the RF detector. A super-regenerative receiver (usually at VHF or higher), takes the detector in and out of regeneration at a super-sonic frequency. The idea is to get more regeneration than the straight regenerative receiver, but in way that you can't hear the "feedback". Super-regenerative detectors are followed by a low pass filter to remove the super-sonic mess. (I know...I've built one in an attempt to get more out of a "sniffer"). Whether this all has anything to do with the name "super" I have no idea !